Calibration

Point source standards (bright stars known to be single) will be observed at each sky location with a minimum of one per hour. PIs should select the closest single (not binary) 5-6th magnitude star from the Yale Bright Star Catalog for each science target. These must be included in the OT with appropriate guide stars, preferably grouped with the corresponding science observation. One option for finding standards is to use the Gemini Telluric standard star search with Spectral Type = "O B A F G K M" and magnitude range = 5 < V < 6.

Photometric Standards

The DSSI photometric precision is ~0.1 mag in R and ~0.2 mag in I at R~14 (Horch et al., 2012), and the pipeline-processed DSSI data will include photometric zero points if executed under photometric conditions and accompanied by a photometric calibrator. Note that programs wishing to do photometry must include 15 minutes (including acquisition overheads) per night for calibrators.

Astrometry

DSSI delivers excellent relative astrometric precision of ~1 mas for objects such as binary stars (Horch et al., 2012). For astrometric calibration observations of a few well-studied binary stars are carried out in twilight during the observing run and used to determine a plate scale and position angle for each camera and applied to the run as a whole, or as changes occur to the optical path.